Method for salvaging electrical equipment and machinery



United States Patent Office 3,078,185) Patented Feb. 19, 1963 1960, Ser.No. 39,737 (Granted under Title 35, US. Code (1952), see. 266) Claims.(Cl. 134-26) The invention described herein may be manufactured and usedby or for the Government of the United States of America forgovernmental purposes without the payment of any royalties thereon ortherefor.

This application is a division of copending application Serial No.821,332, filed June 18, 1959.

This invention concerns a method for removing fuel oil contaminationfrom electrical and mechanical equipment. More particularly, it concernsa cleaning composition and technique for rapid and effective recovery ofelectrical and mechanical equipment which have become flooded and fouledwith fuel oil.

Electrical and mechanical installations and equipment on Navy vesselsare subject to salt water flooding and fuel oil contamination as aresult of battle damage, collision, as a necessary fire control action,or as a result of mechanical and personnel failures in the operation offuel storage and ballasting systems. It is also of the greatestimportance that equipment on Navy vessels and shore installations bereturned to service, often, on emergency basis and at the earliestpossible moment with minimum assistance from trained overhaul men. Itis, furthermore, essential in all cases that damage by corrosion tometal and deterioration to electrical insulation should be prevented orminimized.

Heretofore, equipment on board ships and on shore installations, whichhave become water-logged by flooding or by excessive condensation havebeen recovered by treating them with a water-displacing compositionwhich provides positive displacement of water from metal parts and frominsulating material; said water-displacing composition forms the subjectmatter of US. Patent 2,647,839 which was issued on August 4, 1953, toWilliam A. Zisman and Hayward R. Baker. displacing andcorrosion-inhibiting composition (Spradri) has found wide usage in theNavy as well as in industry as an effective product for returningwater-flooded equipment to service without dismantling and within afewliours after their recovery from submersion.

i Shipboard experience, however, has shown that comp'artment flooding isoften accompanied with fuel oil contamination resulting from damage tofuel lines or from escape of oil cargo. In such cases, the viscous,adherent oil residues resist removal by water and prevent thewater-displacing composition from removing the water which is present.

The present invention involves a cleaning composition and a techniquefor removing burner fuel oils, such as Bunker C orNavy Special, fromelectric motors, electronic equipment, machinery, and the like, whichhave been submerged in sea water and/ or have become contaminated withfuel or waste oils, petroleum, oily residues, along with dirt, grime andtrash. The composition is poured over or preferably, sprayed lightly onco-ntaminated surfaces, followed with water-rinsing to remove thedisplaced contamination and remaining cleaning composition; finally thecleaned electric motors, electronic devices, etc. may be sprayed with awater-displacing composition to remove surface water and then air driedto the point Where they can be returned to service safely.

An object of this invention is to provide a method for The patentedwater- A removing fuel oil, oily Wastes, dirt, and other contaminationfrom water-logged compartments on naval vessels wherein saidcontamination is difficult to remove by conventional cleaning methods.

Another object of this invention is to provide a method for utilizing acleaning composition for removing oil contaminations Without damage toelectrical equipment and insulation.

A further object of this invention is to provide a new method andcomposition for salvaging operations on shipboard, said compositionbeing relatively simple to use, requiring little or no mechanicaltreatment of the affected parts and being moreover equally effectivewith either fresh Water or salt Walter.

It is also an object of this invention to provide a salvage method thatcan be performed by routine maintenance crews on board ship and thatpermit reuse of the flooded equipment in the shortest possible time.While the disclosure that follows is concerned with Navy salvagingoperations, the novel cleaning composition and method may be utilized inany salvaging, reclaiming or cleaning operation in which a persistantoily contaminant is present.

Still other advantages of the invention, and the invention itself, willbecome apparent from the following detailed description of a particularembodiment thereof.

According to the invention, a composition is formulated which consistsof an emulsion of a dispersed hydrocarbon solvent in water andcontaining therein a surfactant or surface-active agent, in an amountsufficient to hold the hydro-carbon solvent and water in a usefulemulsion, and an efiective component, one that is capable of penetratingthe contaminating film which is to be removed. According to the presentinvention, the present cleaning emulsion breaks and displaces adherentfuel oil films by spraying a fine stream of cleaning emulsion on viscousoil contaminations at spraying pressures of about 20 to p.s.i. and thenflushing the sprayed parts with water. Once the contaminating oil filmis broken and pushed back as a result of the present cleaner and thespraying force of the water, it is rendered relatively nonwetting anddoes not contaminate the surface over which it is flushed.

The dispersed hydrocarbon in the cleaning composition is an aliphatictype solvent having a flash point in the vicinity of 140 F. The solvent,as specified for herein, may be a naphtha fraction that meets the flashpoint requirement or it may be the Dry Cleaning Solvent, Type II, whichmeets Federal Specification P-S-66lb. The Amsco 140 Solvent supplied bythe American Mineral Spirits Company is a specific example of acommercially available product that may be used in the presentcomposition. It has an initial boiling point of 364 F., the fractionthereof boiling at 387 F., thus providing a close-cut boiling range fora solvent with a remarkably mild odor. In an oil-in-water emulsion analiphatic'hydrocarbon with a flash point in the vicinity of F.

is less of a fire hazard than the solvents normally used in cleanerswith flash points of about 104 F. As a result of the higher flash point,there is no requirement for a chlorinated hydrocarbon snuffer in orderto suppress the volatile nature of the solvent. The flash point of thesolvent in the vicinity of 140 F. is generally higher than the flashpoint of most contaminating fuel oils with which the solvent will comein contact. It is to be understood, however, that the high flash pointof 140 F. for the aliphatic solvent specified herein is not critical forthe practice of the present invention and that an aliphatic solventhaving a flash point somewhat less than 140 F. may be used withoutreducing the effectiveness of the cleaning emulsion;

The surfactant used in the present composition may be any one of thecommercially available products, for instance, Span 85, Monisol X-l00,Tergitol Monionic NPX, and Pluronic L63, which are surface-active agentsof the non-ionic type. The inclusion of a surface-active agent of thistype, in a relatively small amount of less than 1% and preferablybetween 0.2 and 0.5% by weight of the composition, causes the emulsionto break upon coming in contact with the fuel oil film and releases thesolvent at the point of contact, where it penetrates and dilutes the oilfilm. A surfactant in a relatively small concentration provides anunstable emulsion which has been found useful for the present cleaningcomposition. It has been observed that emulsions of maximumstabilitythose containing surfactants of about 1% or more-do not cut theoil film effectively. On the other hand, compositions which containsurfactants in very low concentrations, those containing about 0.1% orless, form emulsions which break so rapidly that they cannot be handledand sprayed conveniently.

Non-ionic type surfactants may be used effectively with either freshwater or with salt water. Surfactants of this type are mainly polyglycolesters of the fatty acids and polyoxy-alkylene derivatives. Aparticularly effective compound of this type is the polyethylene glycolmonooleate. Emulsions containing 0.25% of this surfactant providecleaning compositions of high cutting power as measured by the area offuel oil which is ruptured and pushed back to expose bare surface. Inaddition to its cleaning power, this composition is a good rustinhibitor and provides protection to the treated surface during thecleaning operation and also after the surface has dried by means of afine film of the composition which remains on the clean surface. Theparticular product which is esterfied to form this compound has anaverage polyethylene glycol molecular weight of about 300 to 600 and thefinal product is usually designated by a number in this range, aspolyethylene glycol 400 monooleate.

An additional component which is included in the present cleaningcomposition is one which allows for rapid penetration of fuel oil filmswithout the need for soaking or for mechanically treating thecontaminated surface to loosen the oily film. Such a material is thefuel oil itself. Its presence in the composition hastens the break up ofthe fuel oil film and causes the oil residue to be pushed back withoutany mechanical agitation. Compositions which are formulated without thefuel oil component were found ineffective as cleaners unless someeroding action was also provided, for instance, a spraying force orscrubbing in order to penetrate the film. The fuel oil added in amountsof from about 3 to about 7% by weight of the composition facilitates inpenetrating the oil film, carrying solvent and surfactant to thesurface. Once such contact with the surface has been established, rapidabsorption of the contaminant oil will occur and the spreading action ofthe cleaner clears large areas of contaminant oil.

Fuel oils most often encountered in salvage work are Bunker C (No. 6burner oil) and the Navy Special fuel oil (No. burner oil). Bunker C oilis described in Modern Petroleum Technology published by the Instituteof Petroleum, London (1946), as the heaviest grade fuel oil sold on themarket with a maximum viscosity as measured by Saybolt Furol 122 F. ofabout 300, and a water and solid content of not more than 2%. The NavySpecial fuel has a maximum viscosity of 40 SSU 122 F. and a solidcontent of not more than 0.10%. The composition of the cleaner depends,of course, on the particular fuel oil found contaminating the salvageoperation. When the fuel oil that may be contaminating is known, thecleaning composition may be prepared in advance and only the watercomponent is added at the time of use. However, when the fuel oil orother contaminant cannot be anticipated in advance, the fuel oilcomponent may be omitted from the cleaning composition as initiallyprepared and the particular oil which is found contaminating a salvageoperation may then be added to the cleaning solution in amounts rangingfrom about 3 to about 7 percent by weight based on the finalcomposition.

The materials originally blended consist of 89.5% aliphatic hydrocarbonsolvent, 10% fuel oil and 0.5% surfactant. During a salvaging operationthis mixture is emulsified with an equal volume of water, or with seawater, to form a composition consisting of 50% water, 44.75% aliphatichydrocarbon, 5% fuel oil and 0.25% surfactant, all percentages byweight.

A specific composition by way of illustration includes:

Components Percent by weight Aliphatic hydrocarbon solvent, flash pointNavy Special fuel oil 5 Polyethylene glycol 400 monooleate 0.25

Seawater 50 The efficiency of the cleaning composition is considerablyincreased by utilizing a spraying technique, for instance, using a finespray of the cleaning emulsion at a pressure of from 20 to about p.s.i.which speeds up and also improves the cleaning process. A fine emulsionspray of about 80 p.s.i. requires less amount of cleaning fluid andprovides the most thorough removal of an oil contaminant without damageto electrical insulation. As a spray cleaner, the emulsion may beejected from an oil spray gun for better penetration, dispersion andcomplete removal of fuel oils. The emulsion is not toxic, nor irritatingto the skin and fire hazard is considerably minimized, so that thecleaner may be used without any special health or safety precautions.

Equipment which is contaminated with a heavy grade fuel oil (Bunker C)is more easily cleaned if the cleaning fluid is initially warmed toabout F. Warming the cleaning fluid has also been found to improve aswell as hasten the removal of other fuel oils but this step is notessential for the removal of other fuels. With the more viscous,adhering Bunker C fuel, however, when the emulsified composition iswarmed slightly above room temperature and used as a fine spray at about80 p.s.i., the cleaner can be utilized more efliciently withconsiderable savings in time and expense. Even under the most drasticand vigorous conditions, the cleaning composition, when used in thismanner, will not damage delicate insulations and windings on electricmotors.

In a simulated salvaging operation, electronic equipment, electricmotors, selected samples of insulating fabrics, tapes, plastics andvarnishes were submerged into synthetic sea water containing on thesurface thereof about /8 of an inch of Navy Special fuel oil. After 24hours the samples were removed and sprayed with the present cleaningsolution containing therein 5% of Navy Special fuel oil. The equipmentand insulating samples were then flushed clean with water and sprayedwith a Waterdisplacing composition, for example, one containingbutanol-l and glyceryl oleate. All accessible parts were sprayed withthis composition to remove as much of the surface water as possible, inparticular from the electromotive equipment. The electric motors were soconstructed that water did not penetrate into the stator or armaturecoils and a high resistance to ground (in the order of several megohms)was obtained as soon as the butanol-water mixture had evaporated fromthe surface by blowing the equipment with heated air. When waterpenetrates into the stator windings, low resistance readings areobtained and additional heating and possibly ad.- ditional treatmentwith the water-displacing composition is required until enough water hasbeen removed to permit no-load operation. Motors operated at no-load fora short time are capable of generating enough internal heat to help dryout the equipment.

In an actual salvaging operation, an integrated procedure for cleaningelectrical and mechanical equipment requires rapid removal of fuel oiland sea water contamination. When equipment wet with sea water is movedto an ox gen-rich atmosphere, such as exposure to air, the ferroussurfaces will rust rapidly causing severe damage to sensitive parts. Iffuel oil contamination is a problem, the cleaning composition is formedand emulsified with about an equal quantity of sea water or fresh waterwhen this is available. Using a spray apparatus, the exterior of theequipment is sprayed thoroughly and when access to the interior of theequipment can be gained by partial disassembly, the equipment is furthersprayed and then rinsed thoroughly with sea water, or fresh water whenthis is available. The emulsion spray and rinsing steps are repeatedwhen necessary to remove all traces of the contaminant.

After the fuel oil contamination has been removed, the equipment isfurther flushed with fresh water in order to remove all traces of seawater. Spray flushing, and whenever possible, immersion and drainingshould be employed to remove all traces of salt water which is injuriousto metals and causes electrical shorts and burn outs in electricalequipment. As much of the water should then be blown from the wetsurface as possible with compressed air, by draining or simply byexposure to the suns rays. All parts and interior surfaces, crevices oropenings should be sprayed with any of the water-displacing compositionsto absorb all remaining traces of Water. Some time should be allowed forthis composition to penetrate, displace and combine with the waterremaining in the equipment. When the water-displacing composition hascombined with all available water, it is evaporated from the surface,preferably by blowing with heated air from an electric blower, but inthe absence of such equipment sufficient time should be allowed for themixture to evaporate completely from the surfaces.

Obviously many modifications and variations of the invention may be madewithout departing from the spirit and scope thereof, and therefore, onlysuch limitations should be imposed as are indicated in the appendedclaims.

What is claimed is:

1. A method for salvaging electrical equipment and machinerycontaminated with fuel oil comprising combining a selected amount offuel oil substantially identical in composition to said fuel oilcontamination to be removed with an aliphatic hydrocarbon having aminimum flash point in the vicinity of 140 F. and a surfactant of thenon-ionic type in an amount that will keep said aliphatic hydrocarbonsolvent and said fuel oil dispersed in an unstable emulsion with water,stirring the newly formed mixture with about an equal volume of water toform an emulsion therewith, applying said emulsion to the contaminatedparts to penetrate said oil contamination and rinsing said parts toremove the emulsion and contamination with water.

2. A method for salvaging electrical equipment and machinerycontaminated with fuel oil comprising the steps of combining a selectedamount of fuel oil substantially identical in composition to said fueloil contamination to be removed with a mixture of an aliphatichydrocarbon solvent having a minimum flash point in the vicinity of F.and a surfactant of the non-ionic type in an amount suflicient tomaintain said aliphatic hydrocarbon solvent and said fuel oil in anunstable emulsion with sea water, stirring the newly formed mixture withabout an equal volume of sea water to form an emulsion therewith,applying said emulsion to the contaminated parts to penetrate the oilcontamination, rinsing said parts to remove the emulsion andcontamination with Water, and spraying the rinsed parts with awater-displacing composition containing butanol1 and glyceryl oleate toremove the surface Water.

3. A method for salvaging electrical equipment and machinerycontaminated with fuel oil comprising combining a selected amount offuel oil substantially identical in composition to said fuel oilcontamination to be removed with a mixture of an aliphatic hydrocarbonsolvent having a miniumum flash point in the vicinity of 140 F. and asurfactant of the non-ionic type in an amount sufficient to maintainsaid aliphatic hydrocarbon solvent and said fuel oil in an unstableemulsion with water, stirring the newly formed mixture with about anequal volume of water to form an emulsion therewith, applying saidemulsion to the contaminated parts to penetrate the oil contamination,rinsing the emulsion and contamination with water and spraying therinsed parts with a water-displacing composition containing butanol-land glyceryl oleate to remove the surface water.

4. The method as disclosed in claim 3 including the step of air dryingthe cleaned parts sufficiently to permit operation of said electricalequipment and machinery.

5. A method for salvaging electrical equipment and machinerycontaminated with fuel oil and sea water comprising the steps ofspraying the contaminated parts with an emulsion containing sea water, aselected amount of fuel oil substantially identical in composition tosaid fuel oil contamination to be removed, an aliphatic hydrocarbonsolvent having a minimum flash point in the vicinity of 140 F. and asurfactant of the non-ionic type in an amount that retains said fuel oiland said aliphatic hydrocarbon solvent in an unstable emulsion with seawater, and rinsing said sprayed parts to remove said emulsion andcontamination with water.

References (Iited in the file of this patent UNITED STATES PATENTS1,198,036 Jackson Sept. 12, 1916 2,134,602 Cohen Oct. 25, 1938 2,671,036Obermeit Mar. 2, 1954 2,748,084 De Lew May 29, 1956 2,866,726 Vance Dec.30, 1958

1. A METHOD FOR SALVAGING ELECTRIICAL EQUIPMENT AND MACHINERYCONTAMINATED WITH FUEL OIL COMPRISING COMBINING A SELECTED AMOUNT OFFUEL OIL SUBSTANTIALLY IDENTICAL IN COMPOSITION TO SAID FUEL OILCONTAMINATION TO BE REMOVED WITH AN ALIPHATIC HYDROCARBON HAVING AMINIMUM FLASH POINT IN THE VICINITY OF 140* F. AND A SURFACTANT OF THENON-IONIC TYPE IN AN AMOUNT THAT WILL KEEP SAID ALIPHATIC HYDROCARBONSOLVENT AND SAID FUEL OIL DISPERSED IN AN UNSTABLE EMULSION WITH WATER,STIRRING THE NEWLY FORMED MIXTURE WITH ABOUT AN EQUAL VOLUME OF WATER TOFORM AN EMULSION THEREWITH, APPLYING SAID EMULSION TO THE CONTAMINATEDPARTS TO PENETRATE SAID OIL CONTAMINATED AND RINSING SAID PARTS TOREMOVE TTHE EMULSION AND CONTAMINATION WITH WATER.